Page 55 - Fertility in Women with Rheumatoid Arthritis Vruchtbaarheid van vrouwen met reumatoïde artritis

of women with RA, and appear to be safe.28 Since active disease is associated with a longer TTP,3 subfertile RA patients may bene t from the preconceptional use of these biologicals, and fewer women would need to end their efforts to build a family because of active disease.
With a higher pregnancy rate and less nulliparity than non-participants, the
participants in this study seemed to be a more fertile selection of the PARA cohort.
Therefore our current results may very well be an underestimation of the real 3 incidence of the total subfertility and their impact on childbearing in the total female
RA population. Since the incidence of subfertility in the PARA cohort was consistent
with other recent studies in female RA patients of reproductive age,3 it is not likely that
selection on subfertility in the recruitment for the original PARA cohort introduced
bias in the current study and affected our current results.
An explanation for the lower pregnancy rate and higher nulliparity among the non-
participants may be that they were less desirous of achieving a pregnancy than the
participants. However, this was not the case. No differences were found between
participants and non-participants in the number of children already present before
the nal PARA participation. Moreover, within the non-participants who did not
achieve a pregnancy during the last PARA episode more women underwent fertility
treatments than the non-pregnant participants, although this difference was non-
signi cant (data not shown). Therefore, the motivation to achieve a pregnancy
appeared not to be diminished in the non-participants.
On the other hand, the cause of subfertility may have indirectly affected patients
in their choice to participate in the current study. Fertility problems that are hard
to treat, e.g. endometriosis, or a severe oligospermia or azoospermia, often have
a poor treatment outcome, not leading to the desired pregnancy. Although the
patients participating in the current study did not show a higher occurrence of these
diagnoses than the general subfertile population, the non-participants were more
often nulliparous. Therefore, we cannot rule out that the prevalence of these hard-to-
treat cases might be more frequent in the non-participant group, and consequently
also in the total RA population. Furthermore, there were more smokers among non-
participants than among participants. This may point toward a less healthy lifestyle,
which in turn is associated with reduced conception rates.29 Details on smoking
behaviour, like package years, are missing in the PARA study, and could not be
analysed further. However, even if all non-participants of whom we know they had
had fertility work-up or fertility treatments had another diagnosis than unexplained
Fertility in RA – fertility assessments
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